Recent Advances in local Anaesthesia in dentistry

1. PRESENTER
DR.K.PRASHANT
III MDS

2.  Introduction
 Newer LA Drugs
 LA Delivery Systems
 CCLAD system
 Jet injectors
 Safety dental syringe
 Devices for intra-osseous anesthesia
 Vibrotactile devices

3.  Newer technologies have been developed that can
assist the dentist in providing enhanced pain relief with
reduced injection pain and fewer adverse effects

4.  Lignocaine Hydrochloride is considered the “Gold
Standard among LA.‟
Two relatively new drugs that have proved to be
equally or more efficient to Lignocaine are
 1. Articaine
 2. Centbucridine

5.  It belongs to the Amide group of local anesthetics.
 It consists of a thiophene ring instead of a benzene
ring and an ester group that is metabolized by
esterases in the tissues.
 Elimination of Articaine is exponential with a half-life
of about 20 minutes.
 Metabolism is both in the liver and plasma
 5-10% secreted unchanged and 90% is metabolized.

6.  1. Articaine has a faster onset of action
 2. Articaine has a longer duration of action
 3. Articaine has a higher success rate
 4. Articaine has a greater potency (1.5 times more
potent)
 5. Systemic intoxication of Articaine is lower
 6. Articaine is a very safe drug

7.  1.7 times greater volume needed for lignocaine 2% to
that of 4% Articaine for achieving the same anesthesia
 Articaine buccal infiltration enhances the
effectiveness of lidocaine IANB
 Duration of action:60-75 min of pulpal anesthesia for
1:100000

8.  Documented Adverse effect: methemoglobinemia,
paresthesia
 Not recommended in children below 4 year and
lactating mother

9.  Synthesized at the Centre for Drug Research of India at
Lucknow, India in the year 1983
 A quinolone derivative with local anesthetic action .
 It has intrinsic vasoconstricting and anti-histaminic
properties.
 Concentration of 0.5% can be used effectively for
infiltration, nerve blocks and spinal anesthesia.

10.  Anesthetic potency 4-5 times greater than that of 2%
lignocaine.
 Onset of action is quicker and duration is longer
 It does not require simultaneous administration of
adrenaline
 It does not effect the CVS parameter due to its
moderate antihistaminic activity and is not likely to
show skin sensitivity.
 Can be used in patient hypersensitive to lignocaine.

11.  An indication for the reversal of soft tissue anesthesia
(lip & tongue numbness).
 Phentolamine Mesylate is a non-selective alpha
adrenergic blocking agent and reverses the effects of
epinephrine and nor-epinephrine on tissues
 Medical uses: diagnosis of pheochromocytoma, tt of HTN
in pheochromocytoma and prevention of tissue necrosis
after norepinephrine extravasation.

12.  The ultimate effect of alpha receptor blockade is
vaso-dilatation.
 Peak concentration is achieved after 20 minutes
and the elimination half-life is 2-3 hours.
 Availabe injectable dose 0.4mg/1.7ml(max.
0.8mg)
 Dose based on amount of local anesthetic
administred
 ½ cartridge of LA :1/2 cartridge of phentolamine
(0.2mg)

13.  Standard Local anesthetic solution are buffered
few mins before injection with sodium
bicarbonate
 PH of buffered dental cartridge of LA ranges
between 7.35 -7.5( i.e.closer to physiologic
range)

14.  Eliminates the sting on injection( greater patient
comfort during inection)
 More rapid onset of action(2 min)
 Reduces tissue and post injection soreness
 Introduces the independent anesthetic action of
CO2
 Introduces catalytic effect of CO2

15.  Direct depressant effect on axon
 Concentrating the local anesthetic inside the
nerve trunk though ion trapping
 Changing the charge of local anesthetic inside
the nerve axon

16.  Used as topical anesthetic able to provide surface
anesthesia for intact skin
 Composed of lidocaine 2.5% and prilocaine 2.5%
 Supplied as a 5g or 30g tube or as an EMLA anesthetic
disc.
 EMLA anesthetic disc is packaged in protective
laminate foil surrounded by adhesive tape.

17.  As topical anesthetic in pediatric patient and
needle phobic patient
 Venipuncture
 Circumcision and gynecologic procedure
 During leg ulcer debridement
Note: should be applied 1 hr before the
procedure.

18.  Patient with congenital or idiopathic
methemoglobinemia
 Infants younger than 12 month
 Known sensitivity to amide type LA

20.  Eutectic mixture of local anesthetics
 Solution at room temperature; gel at body
temperature
 First topical anesthetic specifically designed for
scaling and root planing

23.  Principle of Transcutaneous Electrical Nerve
Stimulation (TENS) which has been used for the relief
of pain.
 Some limitations are increased salivary flow and
inability to use metal instruments freely.

24.  Patient having needle phobia
 Ineffective LA
 Instances where LA cannot be administered
 TMJ(chronic pain)
 Nonsurgical periodontal pain
 Restorative dentistry
 Fixed prosthodontic procedure
 Reversal of soft tissue anesthesia

25.  No need of needle
 No need for injections of drugs
 Patient is in control of the anesthesia
 No residual anesthetic effect at the end of
procedure
 Residual analgesic effect remains for
several hours

26.  Cost of the unit
 Training & ‘Learning curve‘ initial success
may be low but increases with experience
 It is contraindicated in several conditions
1.Heart disease, 2.Seizures,
3.Neurological disorders, 4.Brain tumors,
5.Patients wearing pacemakers and cochlear
implants

27.  A patch that contains 10-20% lidocaine is
placed on the dried mucosa for 15 minutes.
 Hersh et al (1996) studied the efficacy of this
patch and recommended it for use in achieving
topical anesthesia for both maxilla and
mandible.

29.  Jet-injection technology is based on the principle
of using a mechanical energy source to create a
release of pressure sufficient to push a dose of
liquid medication through a very small orifice.
 LA is driven into the subcutaneous tissue without
a needle.

31.  Advantages :
1. Being fast and easy to use,
2. With little or no pain,
3. Less tissue damage, and
4. Faster drug absorption at the injection site
 This technique is particularly effective for
palatal injections
 Marketed as Syrijet ,MED-JET H III, INGEX,
PHARMAJET etc.

32.  Iontophoresis is non-invasive transdermal drug
delivery
 It is a painless modality of administrating
anesthesia.
 After just 10 minutes, the skin is as numb as
after 60 minutes of traditional treatment with
creams.

33.  The method is faster and penetrates deeper
than topical anesthetic creams and is an ideal
alternative for numbing the skin before
injections and biopsies.
 We recommend a Xylocaine topical anesthetic
solution, 40 mg/ml.
 Xylocaine has a positive charge, so connect
the anode (red clamp) to the drug delivery
electrode

35.  Introduced the first CCLAD system in 1997 and was
termed the “WAND” and the subsequent versions
were renamed as “WAND PLUS” and “COMPUDENT”.
In 2001, DENTSPLY International introduced the
 “Comfort Control Syringe – CCS” and similar devices
originating outside USA were; “Quick Sleeper,
Sleeper
 One from France, “Anaeject” and “Orastar” from
Japan.

36.  Wand” has 3 components: Base unit, Foot pedal
and Disposable Handpiece assembly
 Base unit consists of a microprocessor and
connects to the foot pedal and Handpiece assembly
that accepts the LA cartridge.
 LA solution from the cartridge passes through the
microbore tubing in the Handpiece assembly and
needle into the target tissue

37.  Rate of Injection: foot pedal controls the rate of
injection and if aspiration feature is enabled, it
prevents inadvertent intravascular injections.
 1. Slow: 0.005ml/s –PDL injection, Palatal
administration
 2. Fast: 0.03ml/s – buccal infiltrations, nerve block
 3. Turbo: 0.06ml/s

38.  “Single Tooth Anesthesia System – STA System” was
introduced by Milestone Scientific in 2007.
 Its advantages include „Dynamic Pressure Sensing –
DPS‟
 which provides continuous feedback to the user
about the pressure at the needle tip to identify the
ideal needle placement for PDL injections.

39.  Consists of two components; base unit and syringe.
 The most important functions of the unit (injection and
aspiration) can be controlled directly from the syringe.
 Rate of injection: Five different basic injection rate settings
for specific applications: block, infiltration, PDL, IO and
Palatal regions.
 The unit uses two stage delivery rates for every injection.
 It initially expresses the LA solution at an extremely low rate
and after 10 seconds the rate slowly increases to the pre-
programed value for the selected injection technique.

41. 1) Ability to administer small quantities of LA solution
continuously during needle insertion, which anesthetizes the
tissue immediately ahead of the advancing needle.
2) Steady infusion of the anesthetic solution at the target
site reduces the discomfort associated with less controlled
injections.
3) Less pain on injection
5) Less fear of injectiom
8) Ability to perform newer techniques such as
a. AMSA – anterior middle superior alveolar block
b. PDL – periodontal ligament infiltration
c. P-ASA – palatal approach to anterior superior alveolar block.

42.  The use of motor driven perforator to penetrate the buccal
gingiva and bone can be considered as the first modern
technique of IO anesthesia.
 The devices used for this technique, inject the solution into the
cancellous bone adjacent to the root apex. Commonly used
devices are:
i. Stabident
ii. X – Tip
iii. Intraflow

43.  It includes a solid 27 gauge perforator needle with a beveled
tip and a plastic base which fits a latch type slow speed
contra-angle handpiece.
 This perforator creates a small tunnel through attached
gingiva,periosteum and alveolar bone.
 The insertion point of the perforator is in the attached
gingiva, 2mm below the facial gingival margin and midway
between the tooth of intent and immediately adjacent
(distal) tooth.

44.  X – Tip: this system consists of three parts;
the drill, perforator, 25 gauge guide sleeve
 The advantage of this system over Stabident
 the ease with which the perforation could be
located for inserting the needle.
 The drill leads the guide sleeve through the cortical plate
into the cancellous bone.
 The drill portion is removed, leaving the guide sleeve in
place, which directs the needle into the cancellous bone to
deposit the LA solution. Later the guide sleeve is removed
with a hemostat

46.  The Intraflow HTP Anesthesia Delivery System is
an “all in one” system that allows the operator to
perforate the bone and deposit the anesthetic
solution in a single step.
 The device is a dental handpiece equipped with an
injection system built into its body.
 Penetration with this low speed high torque device
is by a single, steady insertion using direct
pressure

47.  Aimed at easing the fear of the needle take
advantage of the gate control theory of pain
management, which suggests that pain can be
reduced by simultaneous activation of nerve
fibers through the use of vibration
 Devices are :vibrajet, dentvibe and accupal

48.  It is a small battery-operated attachment that
snaps on to the standard dental syringe. It
delivers a high-frequency vibration to the needle
that is strong enough for the patient to feel.

49.  It is a cordless, rechargeable, hand held device
that delivers soothing, pulsed, percussive micro-
oscillations to the site where an injection is
being administered.
 Its U-shaped vibrating tip attached to a
microprocessor-controlled Vibra-Pulse motor
gently stimulates the sensory receptors at the
injection site, effectively closing the neural pain
gate, blocking the painful sensation of
injections.

50.  It also lights the injection area and has an
attachment to retract the lip or cheek

51.  A cordless device that uses both vibration and pressure
to precondition the oral mucosa.
 Accupal provides pressure and vibrates the injection
site 360° proximal to the needle penetration, which
shuts the “pain gate,” according to the manufacturer.
 Applying moderate pressure, the unit light up the area
and begins to vibrate. The needle is placed through a
hole in the head of the disposable tip, which is
attached to the motor.

52.  These syringes possess a sheath that locks
over the needle when it is removed from the
patient’s tissues preventing accidental
needle stick injury.
1.Ultra safe syringe, 2.Ultra safety plus XL syringe,
3.Hypo-safety syringe,
4.Rev Vac safety syringe.
 Aim to prevent from the risk of accidental needle
stick injury occurring with a contaminated needle
after local anesthesia administration.

53.  Hand book of local anesthesia by Stanley F.
Malamed
 IOSR Journal of Dental and Medical
Sciences (JDMS)